SUMMARYThe eye movements of a patient with a left lateral medullary infarct (Wallenberg’s syndrome) were recorded using the scleral search coil in magnetic field technique. When asked to look at spontaneously appearing targets, saccades to the left were generally accurate hut those to the right reached the target by multiple step refixation saccades. Large amplitude rightward saccades were possible between two continuously visible targets or when making voluntary saccades in the dark.Vertical saccades, up or down, between spontaneously appearing targets were always associated with a leftward eye movement (lateropulsion). Voluntary vertical saccades between continuously visible targets showed that upward movements had left lateropulsion but downward movements were normal. Vertical voluntary saccades in the dark were oblique, upward saccades showing left lateropulsion and downward saccades showing rightward deviation. The aberrant horizontal components of vertical saccades had amplitude and velocity characteristics for components of normal oblique saccades. Possibly impaired assessment of vertically with incorrect eye position information produced by the infarct accounts for the lateropulsion of saccades in Wallenberg’s syndrome.
Task Dependent Variations of Ocular Lateropulsion in Wallenberg’s Syndrome
